Candelária Formation, Paraná Basin

For other uses, see Candelaria Formation.

Candelária Formation
Stratigraphic range: Late Carnian (Tuvalian) ~231.4–222 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Outcrop map of the Candelária Formation
Type	Geological formation
Unit of	Santa Maria Group
Sub-units	Hyperodapedon & Riograndia Assemblage Zones
Underlies	Caturrita Formation
Overlies	Santa Maria Formation
Lithology
Primary	Mudstone
Other	Sandstone
Location
Coordinates	29.6°S 53.5°W / -29.6; -53.5
Approximate paleocoordinates	42.4°S 14.7°W / -42.4; -14.7
Region	Rio Grande do Sul
Country	Brazil
Extent	Paraná Basin
Type section
Named for	Candelária
Candelária Formation, Paraná Basin (Brazil)

The Candelária Formation, in other literature also referred to as Candelária Sequence,[1][2][3] is a sedimentary formation of the Santa Maria Group (also called Santa Maria Supersequence) in the Paraná Basin in Rio Grande do Sul, southeastern Brazil.[4] The formation dates to the Carnian of the Late Triassic, locally referred to as Tuvalian, from 231.4 to approximately 222 Ma.

The Candelária Formation is composed of mudstones and sandstones deposited in a lacustrine to deltaic (distal floodplain) environment. It overlies the Santa Maria Formation and is partly overlain by and partly laterally equivalent to the Caturrita Formation. The formation comprises two Assemblage zones; the older Hyperodapedon and the younger Riograndia Assemblage Zones. Several cynodonts and other therapsids as well as early dinosaurs were found in the formation in the vicinity of Agudo.

Description

Candelária Sequence in the Paraná Basin

The Candelária Formation or Sequence corresponds to a third-order sequence placed in the Santa Maria Supersequence. The basal portion of the formation consists of a coarsening-upward succession that begins with red mudstones, interbedded with small-scale trough cross-bedded sandstone lenses. Rhythmites and sigmoidal massive to climbing cross-laminated sandstone bodies are also present. This facies association is interpreted as a lacustrine to deltaic (distal floodplain)[5] depositional environment in a humid climate. The formation contains the Hyperodapedon and Riograndia Assemblage Zones.[6][7]

The red beds are divided into a non-fossiliferous portion at the base, and an upper fossiliferous unit. Coprolites and putative rhizoliths are present. A light-colored cross-bedded sandstone also occurs at the top of the formation and represents a river channel. It is delimited by an erosive contact with the underlying red beds.[5]

The Candelária Formation is considered a local equivalent of the Caturrita Formation,[8] which it partly underlies. It overlies the Santa Maria Formation.[9] The formation is correlated with the Ischigualasto Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina.[2]

Basin history

Stratigraphic chart of the Paraná Basin, with the Candelária Formation belonging to the Gondwana II Supersequence

Main article: Paraná Basin § Basin evolution

The megaregional Paraná Basin, covering an approximate area of 1,500,000 square kilometres (580,000 sq mi) in southeastern South America, was in the late Paleozoic and early Mesozoic part of Gondwana, the southern latitude area of Pangea. Before the opening of the South Atlantic, a rifting phase that started in the Jurassic, the basin was connected to the basins of present-day southern Africa. The Candelária Formation forms part of the Gondwana II Supersequence representing the onset of continental deposition in the Paraná Basin. The Triassic paleofauna of the Paraná Basin is correlated with the African faunas of the Omingonde Formation of the Waterberg Basin in Namibia, the Molteno Formation of the Karoo Basin in South Africa and the Fremouw Formation of present-day Antarctica.[10]

Fossil content

Limb bone osteohistology of Brasilitherium riograndensis

Ulna osteohistology of Brasilodon quadrangularis

The formation has provided fossils of therapsids characteristic of the Late Triassic, as well as early dinosaurs.[4]

Group	Fossils	Assemblage zone	Image	Notes
Dinosaurs	Erythrovenator jacuiensis			[11]
	Macrocollum itaquii			[12]
	Dinosauria indet.			[13]
	Archosauromorpha indet.			[14]
Therapsids	Brasilitherium riograndensis	Riograndia	Brasilitherium riograndensis	[2]
	Brasilodon quadrangularis	Riograndia		[2]
	Botucaraitherium belarminoi	Riograndia		[15]
	Irajatherium hernandezi	Riograndia		[2]
	Prozostrodon brasiliensis	Hyperodapedon		[2][16]
	Siriusgnathus niemeyerorum			[14]
	Probainognathia indet.			[14]
Rhynchosaurs	Hyperodapedon sp.	Hyperodapedon		[7][16]
Rhynchocephalians	Lanceirosphenodon ferigoloi	Riograndia		[17]

See also

• List of dinosaur-bearing rock formations
• Chañares Formation, fossiliferous formation of the Ischigualasto-Villa Unión Basin, Argentina
• Santa Juana Formation, contemporaneous fossiliferous formation of south-central Chile
• Molteno Formation, contemporaneous fossiliferous formation of Lesotho and South Africa
• Pebbly Arkose Formation, contemporaneous fossiliferous formation of Botswana, Zambia and Zimbabwe
• Denmark Hill Insect Bed, contemporaneous fossiliferous unit of Queensland, Australia
• Madygen Formation, contemporaneous Lagerstätte of Kyrgyzstan

References

1. Müller et al., 2017, p.543
2. Botha-Brink, 2018, p.7
3. Martinelli et al., 2017, p.528
4. Candelária Formation at Fossilworks.org
5. Pretto et al., 2015, p.2
6. Soares et al., 2014, p.1675
7. Pacheco et al., 2017, p.2
8. Da Rosa & Faccini, 2005, p.21
9. Da Rosa & Faccini, 2005, p.18
10. Milani et al., 2007
11. Rodrigo T. Müller (2020). "A new theropod dinosaur from a peculiar Late Triassic assemblage of southern Brazil". Journal of South American Earth Sciences. in press: Article 103026. doi:10.1016/j.jsames.2020.103026.
12. Müller, Rodrigo Temp; Langer, Max Cardoso; Dias-da-Silva, Sérgio (November 2018). "An exceptionally preserved association of complete dinosaur skeletons reveals the oldest long-necked sauropodomorphs". Biology Letters. 14 (11): 20180633. doi:10.1098/rsbl.2018.0633. ISSN 1744-9561. PMC 6283919. PMID 30463923.
13. Müller et al., 2018, p.545
14. Niemeyer, Agudo at Fossilworks.org
15. Soares et al., 2014, p.1677
16. Marchezan at Fossilworks.org
17. Romo de Vivar et al., 2020

Bibliography

• Botha-Brink, Jennifer; Bento Soares, Marina; Martinelli, Agustín G. (2018), "Osteohistology of Late Triassic prozostrodontian cynodonts from Brazil" (PDF), PeerJ, 5029: 1–26, retrieved 2019-03-25
• Martinelli, Agustín G.; Soares, Marina Bento; De Oliveira, Téo Veiga; Rodrigues, Pablo G.; Schultz, Cesar L. (2017), "The Triassic eucynodont Candelariodon barberenai revisited and the early diversity of stem prozostrodontians" (PDF), Acta Palaeontologica Polonica, 62: 527–542, doi:10.4202/app.00344.2017, retrieved 2019-03-25
• Milani, E.J.; Melo, J.H.G.; Souza, P.A.; Fernandes, L.A.; França, A.B. (2007), "Bacia do Paraná", Cartas Estratigráficas - Boletim de Geociências da Petrobras, Rio de Janeiro, 15: 265–287
• Müller, Rodrigo T.; Pretto, Flávio A.; Stefanello, Micheli; Silva Neves, Eduardo; Dias da Silva, S. (2017), "On a dinosaur axis from one of the oldest dinosaur-bearing sites worldwide" (PDF), Acta Palaeontologica Polonica, 62: 543–548, doi:10.4202/app.00369.2017, retrieved 2019-03-26
• Pacheco, C.P.; Martinelli, A.G.; Pavanatto, A.E.B.; Soares, M.B.; Dias da Silva, S. (2018), "Prozostrodon brasiliensis, a probainognathian cynodont from the Late Triassic of Brazil: second record and improvements on its dental anatomy", Historical Biology, 30 (4): 475–485, doi:10.1080/08912963.2017.1292423, hdl:11336/94044, retrieved 2019-03-26
• Pretto, Flávio A.; Schultz, Cesar L.; Langer, Max C. (2015), "New dinosaur remains from the Late Triassic of southern Brazil (Candelária Sequence, Hyperodapedon Assemblage Zone)" (PDF), Alcheringa, 39 (2): 1–10, doi:10.1080/03115518.2015.994114, retrieved 2019-03-26
• Romo de Vivar, Paulo R.; Martinelli, Agustín G.; Schmaltz Hsiou, Annie; Bento Soares, Marina (2020), "A new rhynchocephalian from the Late Triassic of southern Brazil enhances eusphenodontian diversity", Journal of Systematic Palaeontology, 18 (13): 1103–1126, doi:10.1080/14772019.2020.1732488
• Da Rosa, Átila Augusto Stock; Faccini, Ubiratan Ferrucio (2005), "Delimitação de blocos estruturais de diferentes escalas em seqüências mezosóicas do Estado do Rio Grande do Sul: implicações bioestratigraficas", Gaea, 1: 16–25, retrieved 2019-03-25
• Soares, Marina B.; Martinelli, Agustín G.; De Oliveira, Téo V. (2014), "A new prozostrodontian cynodont (Therapsida) from the Late Triassic Riograndia Assemblage Zone (Santa Maria Supersequence) of Southern Brazil", Anais da Academia Brasileira de Ciências, 86 (4): 1673–1691, doi:10.1590/0001-3765201420140455, hdl:10183/119079, PMID 25590707, retrieved 2019-03-26

Further reading

• Pavanatto, A.E.B.; Pretto, F.A.; Kerber, L.; Müller Da Rosa, R.T.A.S.; Dias da Silva, S. (2018), "A new Upper Triassic cynodont-bearing fossiliferous site from southern Brazil, with taphonomic remarks and description of a new traversodontid taxon", Journal of South American Earth Sciences, 88: 179–196, doi:10.1016/j.jsames.2018.08.016